I'm a new user and was testing the Open_Historical and Close_Historical Functions using the symbol USO. I tested the date range between 4/29/2016 and 5/4/2016. The correct prices were returned on 4/29. On 4/30 and 5/1, N/A was returned since (I assume) it was the weekend and the market was closed. Correct prices were returned on Mon 5/2 and Wed 5/4 but N/A was returned for prices on Tue 5/3. All function calls were of the form =Close_Historical("USO","date") or =Open_Historical("USO","date"). Is the opening and closing price data for USO on 5/3/2016 missing?